The immune system has different possible ways of reacting. A decisive step for the type of immune response is the stimulation of different T-cell subpopulations. So called Th1 cells predominantly produce cytokines that stimulate a cellular immune response (IFN-y, IL-12, IL-2), for instance to pathogens and vaccines. In contrast, Th2 cells predominantly produce IL-4, IL-5 and IL-10. These cytokines boost an IgE-mediated allergic reaction and inflammation. Th1- and Th2-related cytokines act antagonistically and the Th1 and Th2 responses are under normal physiological circumstances in a well-controlled balance. Neither the Th1 nor the Th2 response prevails. If the responses are in imbalance, the dominance of either Th1 or Th2 immune responses play a role in several pathological conditions.
WO 2005/039319 and WO 2006/091103 relate to a preparation comprising Bifidobacterium breve and a mixture of non-digestible carbohydrates for non- or partially breast-fed infants as well as the use thereof for the treatment or prevention of immune disorders in non- or partially breast-fed infants. WO 2005/039597 relates to the use of acid oligosaccharide and neutral oligosaccharide for enhancing the immune system and the treatment and/or prevention of immune system related disorders. WO 01/642255 relates to a nutritional composition comprising a prebiotic for enhancement of an immune response. WO 2004/0938998 and WO 2004/0938999 relate to an immunomodulatory products obtained from a Bifidobacterium culture.
Much effort is dedicated to find further solutions for balancing and stimulating the immune system.